Data Show Sepracor's Lunesta(R) Improved Insomnia in Patients with Co-Existing Generalized Anxiety Disorder.

Results Presented at American College of Neuropsychopharmacology Annual Meeting

MARLBOROUGH, Mass. -- Sepracor Inc. (Nasdaq: SEPR) today announces the presentation of results from a Phase IV, 595-patient, double-blind, placebo-controlled, ten-week study evaluating the efficacy and safety of LUNESTA([R]) brand eszopiclone in patients with insomnia and co-existing Generalized Anxiety Disorder (GAD). The results will be presented today at the annual meeting of the American College of Neuropsychopharmacology in Hollywood, Fla.

In this study, patients who met DSM-IV([R]1) criteria for both insomnia and GAD were randomized to receive nightly LEXAPRO([R])brand escitalopram oxalate 10 mg, which is approved for the treatment of GAD, and either LUNESTA 3 mg (n=294) or placebo (n=301) for the first eight weeks, followed by a two-week period in which patients discontinued study drug but continued receiving escitalopram and placebo. Sleep efficacy was assessed using patient-reported measures of sleep onset, total sleep time (TST), and wake time after sleep onset (WASO; a sleep maintenance measurement of the amount of time spent awake after initially falling asleep). Symptoms of GAD were assessed using the clinician-rated HAM-A scale (Hamilton Anxiety Rating Scale, a standard scale used to assess anxiety in clinical trials and consisting of a list of symptoms commonly associated with anxiety). Study completion rates were similar (approximately 78%) in both the placebo-escitalopram and LUNESTA-escitalopram treatment groups.

Since anxiety and depression frequently co-exist, symptoms of depression were also evaluated using the clinician-rated HAM-D17 (Hamilton Depression Rating Scale) throughout the study. The Hamilton Depression Rating Scale is a standard scale used to assess depression in clinical trials and consists of a list of symptoms commonly associated with depression.

As compared with patients in the placebo-escitalopram treatment group, patients in the LUNESTA-escitalopram treatment group showed statistically significant (p < 0.05) improvements from baseline in sleep onset, TST, WASO and number of awakenings, during each double-blind assessment week and when averaged over the 8-week, double-blind treatment period.

The LUNESTA-escitalopram group demonstrated reductions from baseline in HAM-A and HAM-D17 scores that were statistically significantly greater (p < 0.05) than those seen in the placebo-escitalopram group during each assessment week of the 8-week, double-blind treatment period. LUNESTA was well tolerated over the treatment period.

"Patients suffering from insomnia frequently have co-existing physical and psychiatric illnesses," said Mark H.N. Corrigan, M.D., Executive Vice President, Research and Development at Sepracor. "Studies indicate that approximately 10 percent of the adult population suffers from chronic insomnia and that in approximately 80 percent of these patients, insomnia is co-existing with other psychiatric and medical illnesses. Sepracor continues to study the effect of the treatment of insomnia with LUNESTA in patients with a co-existing disease or condition. To date, our Phase IV program has examined how LUNESTA can effectively treat insomnia in patients with co-existing depression, pain, menopause and now, anxiety."

An estimated 36 percent of adult Americans reported suffering from either chronic or occasional insomnia in the last year2. Symptoms of insomnia include difficulty falling asleep, awakening frequently during the night, waking up too early, an inability to fall back to sleep, or awakening feeling unrefreshed.

About LUNESTA

LUNESTA is indicated for the treatment of insomnia in patients 18 years of age and older who are experiencing difficulty falling asleep and/or maintaining sleep through the night. LUNESTA is not indicated as a treatment for anxiety, depression or any other medical or psychiatric disorder. LUNESTA is available in 1 mg, 2 mg and 3 mg tablets and treatment should be individualized based on patient age, history and insomnia symptoms. LUNESTA is a Schedule IV controlled substance.

Important Safety Information

LUNESTA is indicated for the treatment of insomnia. LUNESTA is not indicated for the treatment of anxiety or depression. LUNESTA works quickly and should only be taken immediately before bedtime. Patients should have at least eight hours to devote to sleep before becoming active. Patients should not engage in any activity after taking LUNESTA that requires complete alertness, such as driving a car or operating machinery. Patients should use extreme care when engaging in these activities the morning after taking LUNESTA. Patients should not use alcohol while taking any sleep medicine. Most sleep medicines carry some risk of dependency. Patients should not use sleep medicines for extended periods without first talking to their doctor. Patients should see their doctor if they experience unusual changes in thinking or behavior, or if sleep problems do not improve in 7 to 10 days as this may be due to another medical condition. Side effects may include unpleasant taste, headache, drowsiness and dizziness.

About Sepracor

Sepracor Inc. is a research-based pharmaceutical company dedicated to treating and preventing human disease by discovering, developing and commercializing innovative pharmaceutical products that are directed toward serving unmet medical needs. Sepracor's drug development program has yielded a portfolio of pharmaceutical products and candidates with a focus on respiratory and central nervous system disorders. Sepracor's corporate headquarters are located in Marlborough, Massachusetts.

Forward-Looking Statement 

This news release contains forward-looking statements that involve risks and uncertainties, including statements with respect to the safety, efficacy and potential benefits of LUNESTA brand eszopiclone. Among the factors that could cause actual results to differ materially from those indicated by such forward-looking statements are: Sepracor's ability to fund, and the results of, further clinical trials; the timing and success of submission, acceptance, and approval of additional regulatory filings; the scope of Sepracor's patents and the patents of others; the commercial success of LUNESTA; any changes in the use and/or label of LUNESTA; the ability of the company to attract and retain qualified personnel; and certain other factors that are detailed in the company's quarterly report on Form 10-Q for the quarter ended September 30, 2006 filed with the Securities and Exchange Commission.

In addition, the statements in this press release represent Sepracor's expectations and beliefs as of the date of this press release. Sepracor anticipates that subsequent events and developments may cause these expectations and beliefs to change. However, while Sepracor may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing Sepracor's expectations or beliefs as of any date subsequent to the date of this press release.

1Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition

2 Ancoli-Israel et al. SLEEP. 1999;22 (suppl 2):S347-S353

LUNESTA is a registered trademark of Sepracor Inc. LEXAPRO is a registered trademark of Forest Laboratories, Inc. DSM-IV is a registered trademark of the American Psychiatric Association.

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visit Sepracor's web site at www.sepracor.com.